Windows BSOD Error 0x000000AB — SESSION_HAS_VALID_POOL_ON_EXIT Fix

What Does This Error Mean?

The 0x000000AB blue screen is called SESSION_HAS_VALID_POOL_ON_EXIT. It means a Windows session ended while it still had memory allocated — memory that should have been freed but was not. This is almost always caused by a buggy driver that is not properly cleaning up memory when a user logs off or when Windows shuts down. It typically appears at shutdown or when switching users rather than during normal use.

Affected Models

Windows 10
Windows 11
Windows Server 2019
Windows Server 2022

Common Causes

A device driver has a memory leak and is not releasing allocated memory when the Windows session ends
A recently installed or updated driver is incompatible with your current version of Windows
A display adapter driver (GPU driver) is not properly releasing session resources during shutdown
Third-party security software or a system utility is allocating session memory and not cleaning it up
Windows Session Manager is failing due to corrupted system files in the kernel components

How to Fix It

Update your graphics (GPU) driver first, as display drivers are the most common cause. Visit your GPU manufacturer's website — NVIDIA, AMD, or Intel — and download the latest driver for your graphics card.

Do not rely on Windows Update for GPU drivers. Always get them directly from the manufacturer's website for the most current version.
If the error started after a driver update, roll back that driver. Open Device Manager, right-click the device, choose Properties > Driver tab > Roll Back Driver.

Roll Back Driver is only available if Windows saved the previous driver version. If it is greyed out, you will need to download the older version manually.
Enable Driver Verifier to identify the problematic driver. Open Command Prompt as Administrator, type: verifier — then follow the wizard to enable standard settings for all drivers.

Driver Verifier stresses drivers deliberately to expose the faulty one. The next crash will identify the exact driver. Disable Verifier after finding the culprit.
Check Windows Event Viewer for clues. Open Event Viewer (search in Start menu), go to Windows Logs > System, and look for critical errors around the time of the crash.

Look for entries that mention driver names, service failures, or memory pool errors. This can point directly to the problem.
Run sfc /scannow in an elevated Command Prompt to repair any corrupted Windows kernel files that may be contributing to the session cleanup failure.

Follow this with DISM /Online /Cleanup-Image /RestoreHealth for a more thorough repair of Windows core components.

When to Call a Professional

If updating and rolling back drivers does not resolve this, a technician can use Windows debugging tools to identify exactly which driver is responsible. This requires reading memory dump files generated by the crash, which is a technical process. Bring the crash dump file (found in C:\Windows\Minidump) to help the technician diagnose faster.

Frequently Asked Questions

Why does this error only happen at shutdown?

The error occurs at shutdown because that is when Windows tries to end all sessions and free up all memory. If a driver is leaking memory, Windows only discovers the problem when it tries to clean everything up. During normal use, the leak builds up silently without causing a visible problem.

What is a memory pool in Windows?

A memory pool is a reserved area of RAM that Windows gives to drivers and system processes. There are two types: paged pool and non-paged pool. Drivers must request memory from the pool and return it when done. If a driver never returns the memory — a 'memory leak' — the pool fills up or causes errors like this one.

How do I find the crash dump file to help diagnose this?

Crash dump files are saved automatically in C:\Windows\Minidump. Each crash creates a small file with a date and time in the name. You can open these with Windows Debugging Tools (WinDbg), which is a free download from Microsoft. A technician or developer can read these files to identify exactly which driver caused the crash.